package org.litesoft.p2pchat;

import java.net.*;

// Copyright Status:
//
// All Software available from LiteSoft.org (including this file) is
// hereby released into the public domain.
//
// It is free!  As in, you may use it freely in both commercial and
// non-commercial applications, bundle it with your software
// distribution, include it on a CD-ROM, list the source code in a book,
// mirror the documentation at your own web site, or use it in any other
// way you see fit.
//
// NO Warranty!
//
// All software is provided "as is".
//
// There is ABSOLUTELY NO WARRANTY OF ANY KIND: not for the design, fitness
// (for a particular purpose), level of errors (or lack thereof), or
// applicability of this software.  The entire risk as to the quality
// and performance of this software is with you.  Should this software
// prove defective, you assume the cost of all necessary servicing, repair
// or correction.
//
// In no event unless required by applicable law or agreed to in writing
// will any party who created or may modify and/or redistribute this
// software, be liable to you for damages, including any general,
// special, incidental or consequential damages arising out of the use or
// inability to use this software (including but not limited to loss of
// data or data being rendered inaccurate or losses sustained by you or
// third parties or a failure of this software to operate with any
// other programs), even if such holder or other party has been advised
// of the possibility of such damages.
//
// NOTE: Should you discover a bug, have a recogmendation for a change, wish
// to submit modifications, or wish to add new classes/functionality,
// please email them to:
//
//        changes@litesoft.org
//

/**
 * @author  George Smith
 * @version 0.3 02/02/02 Added IllegalArgument.ifNull for all public params that may not be null
 * @version 0.2 01/28/02 Refactored and Added Licence
 * @version 0.1 12/27/01 Incorporated into p2pchat
 * @version 0.0 --/--/98 Initial Version
 */
public class ThisMachine
{
    private ThisMachine()
    {
    }          // private Constructor!

    private static InetAddress[] OurInetAddresses;

    public static String getName()
    {
        if ( !FetchOurInetAddresses() )
            return "";

        return OurInetAddresses[ 0 ].getHostName();
    }

    public static String getIPAddress( int IPindex )
    {
        byte[] zAddress = getNthAddress( IPindex );
        if ( zAddress == null )
            return null;
        String z = "";
        for ( int j = 0 ; j < zAddress.length ; j++ )
            z += "." + (((int) zAddress[ j ]) & 255);
        return z.substring( 1 );
    }

    private static byte[] getNthAddress( int IPindex )
    {
        if ( FetchOurInetAddresses() )
            if ( (0 <= IPindex) && (IPindex < OurInetAddresses.length) )
                return OurInetAddresses[ IPindex ].getAddress();
        return null;
    }

    private static synchronized boolean FetchOurInetAddresses()
    {
        if ( OurInetAddresses != null )
            return true;

        try
        {
            OurInetAddresses = InetAddress.getAllByName( InetAddress.getLocalHost().getHostName() );
        }
        catch ( UnknownHostException e )
        {
            OurInetAddresses = null;
        }

        return (OurInetAddresses != null);
    }
}
